micronaut-core management endpoints vulnerable to drive-by localhost attack

Vulnerability Description

Micronaut Framework is a modern, JVM-based, full stack Java framework designed for building modular, easily testable JVM applications with support for Java, Kotlin and the Groovy language. Enabled but unsecured management endpoints are susceptible to drive-by localhost attacks. While not typical of a production application, these attacks may have more impact on a development environment where such endpoints may be flipped on without much thought. A malicious/compromised website can make HTTP requests to `localhost`. Normally, such requests would trigger a CORS preflight check which would prevent the request; however, some requests are "simple" and do not require a preflight check. These endpoints, if enabled and not secured, are vulnerable to being triggered. Production environments typically disable unused endpoints and secure/restrict access to needed endpoints. A more likely victim is the developer in their local development host, who has enabled endpoints without security for the sake of easing development. This issue has been addressed in version 3.8.3. Users are advised to upgrade.

References

• https://github.com/micronaut-projects/micronaut-core/security/advisories/GHSA-583g-g682-crxf
• https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simple_requests